1. Field of the Invention
This invention relates to an improved, manually actuated, hydraulic device to provide a penile erection for human males who suffer the dysfunction of erectile impotence.
2. Description of the Prior Art
The normal male achieves an erection when a multitude of small blood vessels within a long cylindrical section on each side of the penis called the corposum cavernosum fills with blood as a result of an increase in the vessels' output resistance to blood flow. There are two such parallel cylinders in the penis (the plural being the corpora cavernosa) which simultaneously become engorged with blood, thereby producing a penile erection. Unfortunately, there are 10 million men in the United States alone who are unable to achieve a penile erection.
There are many causes for impotency in the human male, both psychological and physiological. Among the physiological causes are: long term diabetes, damage to the spinal cord, multiple sclerosis, a surgical procedure in the lower abdomen that has caused nerve damage in the genital region, and advanced age. Such impotence often destroys the male's psychological well being, and often seriously disrupts or even causes the dissolutionment of an otherwise fulfilling relationship. It is therefore not surprising to find that the patent art is replete with examples of artificial penile erection devices.
One of the earliest prosthetic devices whose object was to achieve a penile erection is described by Henderson in U.S. Pat. No. 1,133,958 (March 1915). This device suggests the use of an external truss to stiffen the penis by preventing the back-flow of blood. Since the truss is removable, it is a simple matter to obtain a normal flaccid state. However, the external truss mechanism also prevents in-flow of blood and, therefore, cannot provide the five conditions required of a normally erect penis; namely, during erection the penis should become longer, thicker, harder, stiffer, and have a generally upward angle.
Kalnberz, in U.S. Pat. No. 3,832,996 (September 1974), describes two stiff rods designed to be implanted in the corpora cavernosa to attain a penile erection. Although this system provides a longer, thicker, and stiffer erectile state, it does not provide a generally upward angle, and the flaccid state is no longer achievable.
An improved rod is described by Barrington in U.S. Pat. No. 4,151,840 (May 1979), which rod provides a longer, thicker, and stiffer erectile state. Furthermore, the device can be bent downwardly by hand to achieve the flaccid condition. However, in the flaccid condition, the penis is just as long and thick as in the erectile state; also, it is unnaturally stiff and hard.
A manually actuated fluid driven system is described by Strauch et al in U.S. Pat. No. 3,853,122 (December 1974). One drawback in the Strauch et al system is that the required energy for moving the working fluid from the storage container or reservoir thereof must be obtained by manually squeezing the reservoir. A disadvantage of this design is that if the container is large enough to hold a volume sufficient to cause an appreciable change in size between the erectile and flaccid states, then it is too large to be placed in the scrotum. If the fluid container is placed in the abdomen (where it must be located just under the skin so that it can be readily manipulated), it would cause some preceptible abdominal distortion, and would certainly be distinctly felt by the man in whom it was implanted. Further, another difficulty is that fluid exits the region of the penis automatically through a metering means not under external control. The penis therefore could become flaccid too quickly, or could take an unreasonably long time to become flaccid, all depending upon the configuration of the metering means.
Buuck, in U.S. Pat. No. 3,954,102 (May 1976), describes a manually actuated, fluid driven, inflatable penile prosthesis with two cylinders in the corpora cavernosa. The Buuck prosthesis achieves the erectile goals of a longer, thicker, harder, and stiffer penis with a generally upward angle during erection, and also provides a physiologically normal flaccid state. Furthermore, the Buuck invention overcomes one shortcoming of the Stauch et al invention in that it utilizes a large reservoir but that the fluid container is placed deep inside the abdomen where it cannot be felt but where it can be operated remotely by a pump located in the scrotum. However, this device still has certain major shortcomings. For example, when the penis is in the erectile state, its upward angle may not reach that achieved in a normal male. Further, the pump and release valve are located in the scrotum, which is one of the body sites most disposed to postoperative discomfort and infection. The Buuck device requires multiple strokes of the pump within the scrotum to achieve an erection, which could require one or more minutes of pumping, especially if the patient does not have the manual dexterity required for pumping a small bulb located within the scrotum. Furthermore, the release valve in the scrotum must be held for on the order of ten to fifteen seconds to return the penis to the flaccid state. Also, a comparatively large reservoir is required by Buuck because fluid cannot be added after implant without surgical intervention. As a consequence of the large reservoir and small displacement pump used by Buuck, it is possible to permanently distend or even rupture the stiffener cylinders by excessive pumping. Additionally, because of the many separate pieces of tubing and other parts required by the Buuck device it is necessary to fill and then assemble the many separate parts during the surgical implant. This is a time consuming and therefore costly procedure and can lead to leaking and broken connections.
A further element of the prior art is U.S. Pat. No. 4,009,711 (March 1977), which issued to Uson, and which describes a non-distensible portion of a stiffener cylinder that is placed in the root of the corpus cavernosum, and a distensible portion that is located within the pendulous portion of the corpus cavernosum. Although there may be valid reasons to provide a structure such as that described by Uson, it is disadvantageous to have a considerable portion of the stiffener cylinder located within the root of the corpus cavernosum if it is not pliable and distensible. In this regard, some shortcomings of the Uson device are that the penis does not feel natural in the flaccid condition because there is a rigid object just beneath the skin at the base of the penis. Furthermore, the shape of the penis in the flaccid condition is not physiologically normal, nor is there stress relief provided for the elastomer stiffener cylinder during the flaccid state (which is most of the time) because the cylinder does not begin its downward curve while still supported within the root of the corpus cavernosum. Additionally, a greater extended length of the penis in the erectile state cannot be achieved because the cylinder does not begin its extendible portion within the root of the corpus cavernosum.
All of the three patents as described immediately above, namely Strauch et al (U.S. Pat. No. 3,853,122), Buuck (U.S. Pat. No. 3,954,102) and Uson (U.S. Pat. No. 4,009,711), require equipment to be located outside of the corpora cavernosa; this is a disadvantage, because the more extensive is the surgery and the number of devices within the human body, the greater is the risk of infection and the possibility that some interconnecting tubing will become detached, broken or twisted closed. Ideally, surgery would be limited to only the penis. Because others are aware of this desire for a minimal implant, there is additional prior art that describes devices requiring the implantation to be only within the penis while trying to obtain more physiologically normal erectile and flaccid states.
In one embodiment of an invention by Burton, U.S. Pat. No. 4,267,829 (May 1981), FIGS. 5 and 6 show a penile erection device which has no portion of the system outside of the corpus cavernosum. The Burton invention obtains rigidity by diminishing the diameter of a front section of the penile implant while stiffening a rear portion of the pendulous section of the implanted cylinders. An advantage of this design is that no part of the device is outside of the pendulous penis and its root. A significant disadvantage of the Burton design, as shown in FIG. 5 of the patent, is that when the erectile state is desired, most of the pendulous portion of the penis is, in fact, reduced in diameter which is entirely contrary to that which is physiologically normal.
In U.S. Pat. No. 4,318,396 by Finney (March 1982), a specific embodiment shown in FIGS. 10 and 11 (flaccid and erectile states, respectively), again illustrates a penile erection device entirely contained within the corpus cavernosum. In this design, fluid is pushed from a rear section of the pendulous portion (but not the root) into the front portion, therefore making the penis rigid. A disadvantage of this design is that the pendulous portion decreases in length during erection which again is entirely contrary to normal physiology.
Another patent by Finney, U.S. Pat. No. 4,353,360 (October 1982), again shows a device entirely implanted within the corpus cavernosum. This invention shows fluid from an outer flexible cylinder being pumped into an inner cylinder by manually pumping at the base of the pendulous portion of the penis. Again this design has the disadvantage that the erectile state is obtained by removing fluid from the outer cylinder of the implant, thus decreasing the diameter of the penis during erection as compared to its diameter in the flaccid state. Again this is contrary to normal physiology.
Still another invention by Finney, U.S. Pat. No. 4,364,379 (December 1982), once more teaches a device implanted entirely within the corpus cavernosum. In this case fluid is pumped from the base portion of the pendulous section of the device into the tip portion. This again is contrary to normal physiology, because in the erectile state, the diameter of the penis at its base where it joins the body is reduced, rather than increased. Furthermore, the decreased base diameter reduces the stiffness of the prothesis at its most vital point. Therefore the erectile state may not maintain a normal upward angle during sexual activity.
Another element of the prior art is U.S. Pat. No. 4,399,812 by Whitehead (August 1983). Again in this design stiffness during the erectile state is obtained by pumping fluid from the rear part of the pendulous portion of the penis into the front portion. The Whitehead design is again contrary to normal physiology because it shortens the penis during the erectile state which is undesirable.
The last of the inventions described in issued patents to be discussed herein in U.S. Pat. No. 4,407,278 (October 1983) by Burton et al. The design described by Burton et al is again a means of manually pumping fluid from one portion of a cylinder contained within the corpus cavernosum to the distal portion of that cylinder contained in the pendulous portion of the penis. In this case the fluid is manually pumped from a root portion of the cylinder. The Burton et al invention still requires manual pumping and from a particularly awkard place, i.e., between the man's legs just behind the scrotum. It may be quite difficult in one push from such an awkard place to drive enough fluid at a high enough pressure to cause rigidity of the portion of the cylinder contained in the pendulous section of the corpus cavernosum. Furthermore, the Burton et al invention does not have a sufficiently long rigid portion of the cylinder in the root of the corpus cavernosum during the erectile phase. Thus the device described by Burton et al may not provide sufficient stiffness and upward angle to give the penis a reasonably normal erectile state.
A copending patent application Ser. No. 476,931 filed by Fischell on Mar. 21, 1983, describes a penile erection device that is improved by eliminating a pump in the scrotum and by effecting the desired pumping action with a single thrust, but still requires two parts of the system to be implanted outside of the penis itself. The disadvantage of this design is that it requires more extensive surgery as compared with implanting the prothesis entirely within the corpus cavernosum. Similarly, a second copending application by Fischell, Ser. No. 526,893, filed Aug. 26, 1983, includes parts of the penile erection device that are outside of the penis itself, but this device includes a pressure-actuated mechanism that eliminates manual pumping to effect the erectile state.
The entire prior art cited above teaches away from the invention disclosed herein. The present invention is an inflatable penile prothesis entirely contained within the corpus cavernosum which allows fluid to be forced from a section within the root of the corpus cavernosum (i.e., within the body itself) into the pendulous portion of the corpus cavernosum thus allowing the erectile state to be physiologically normal by making it harder, longer, thicker, and at a rigidly held, upward angle without any pumping of fluid.